Slush pump



July 3, 1934. 1 sToEsLlNG ET AL SLUSH PUMP l .1 n www@ x m w 5 m Mm V m m a5 a d I Km Mul l M S f lf .UI ma@ I 5 6 5 f s Qml NQ M e 5 4 2 i i ,M 0 M a S@ My W y M C5 /QQ .mi NY Q\\ KK W% mK.

mw H Q w .m k\ NM. WW.

QQ mw Nm MQ MS QQ w *W um m Juy 3, 1934. STOESLING ET AL 1,964,932

` sLUsH PUMP 2`SheetS-Sheet 2 Filed June l, 1931 v amd/6* 57'0551, we,

Patented July 3, 1934 PATENT OFFICE SLUSH PUB/[P Ludwig Stoesling and Howard Field, Jr., Monrovia, and Charles E. Barlow, Hollywood, Calif.

Application June l, 193i, Serial No. 541,232

8 Ciaims.

Our invention relates to pumps, and relates to a cylinder-piston mechanism suitable for use in heavy service pumps, such as slush pumps employed in the rotary drilling of wells.

Slush pumps, and other pumps employed for carrying liquids with abrasive materials therein, are subject to very severe and rapid wear in the moving parts thereof so that such parts must be frequently replaced. This is especially so in the cylinder-piston mechanism of such pumps owing to the fact that abrasive materials enter between the frictionally engaging faces of the piston and cylinder. In attempting to avoid this condition, expansible rubber pistons are eX- tensively used, and owing tc the pressure eX- erted by the rubber parts of the piston against the wall of the cylinder, a very large coefficient of friction is produced.

Our invention comprehends a cylinder and piston mechanism in which the frictionally engaging walls of the cylinder and piston thereof are protected from the materials being pumped so that abrasives from the material being pumped cannot enter the minute space between the frictionally engaging walls of the cylinder and the piston, thereby avoiding the rapid wear of cylinders and pistons due to such cause. Also, the coeicient of friction between the piston and cylinder wall may be very greatly reduced, as the need for employment of pressure of the peripheral faces of the piston with the cylinder wall to prevent entrance of abrasives therebetween is not present, and the piston therefore may be made to slide freely in the cylinder.

It is an object to provide in a pump a cylinder and a piston having means for feeding a protective fluid thereto in such a manner that such protective iuid will prevent entry of the pumped fluid, or abrasives from the pumped fluid, into 4G the minute annular space between the circumferential wall of the piston and the cylinder wall.

A further object of the invention is to provide a cylinder-piston mechanism of the above character having means for maintaining a body of protective fluid at the ends of the minute annular space between the circumferential wall of the piston and the cylinder wall.

It is a further object of the invention to provide a cylinder-piston mechanism having a cyl- 50 inder with a piston operative therein, there being a pumping space of variable volume adjacent the end of the piston, and an annular auxiliary space between the pumping space' and the 55 engagement surfaces of the piston and cylinder,

(Cl. 10S-204) together with means for feeding a protective fluid to the auxiliary space in a manner to prevent entry of the pumped fluid into the auxillary space.

It is a further object of the invention to provide a cylinder-piston mechanism having a cylinder and a piston, said cylinder and piston having walls which overlap in a manner to form an auxiliary space of variable volume between the pumping space and the frictionally engaging portions of the cylinder and piston, and means for positively feeding a protective uid to this auxiliary space.

It is a further object of the invention to provide a cylinder member having an outer Wall and an inner wall projecting inwardly from the end of the outer wall so as to form an annular space between the outer and inner walls, and a piston having a tubular wall projecting into the space between the outer and inner walls of the cylinder member.

It is a further object of the invention to provide a cylinder-piston mechanism which may be readily made in the form of an accessory to be mounted in the cylinder chambers of pumps now in use.

A further object of the invention is to provide parts for use in mounting our improved cylinder-piston mechanism in a standard or known form of pump.

A further object of the invention is to provide a simple form of centralizing means for the cylinder-piston mechanism wherein the cylinderpiston mechanism is centralized with the cylinder chamber of a pump by parts axially engaging the ends of the cylinder member of the cylinder-piston mechanism.

Further objects and advantages of the invention will be made evident throughout the following part of the specification.

1ieferring to the drawings, which are for illustrative purposes only,

Fig. l is a longitudinally sectioned View showing a preferred embodiment of our invention mounted in the cylinder chamber and forming part of the pump.

Fig. 2 is an enlarged fragmentary sectional view for clearly showing the overlapping walls of the cylinder-piston mechanism forming the auxiliary chamber which receives the protective fluid.

Fig. 3 is a cross section on a plane represented by the line 3 3 of Fig. l.

Fig. 4 is a cross section on a plane represented by the line 4-4 of Fig. 1.

Fig. 5 is a cross section on a plane represented by the line 5*-5 of Fig. 1.

Fig. 6 is a fragmentary sectional view showing an alternative form of our invention.

In Fig. 1 we show the body 10 of a pump with which our invention is directly concerned, such body having a cylindrical wall 11 and end walls 12 and 13 forming a cylinder chamber 14 from which walls 15 and 16 extend upwardly so as to provided fluid passages 17 and 18 leading upwardly from the ends of the cylinder chamber. In the accepted practice of mud pump construction, the cylinder chamber 14 is adapted to receive a cylinder wall or liner which may be readily removed therefrom and replaced when worn, and to receive such replaceable cylinder wall or liner the wall 11 is generally provided with an inwardly projecting annular wall portion 20. In the standard pump construction the end wall 12 is provided with an opening 21 which receives a packing box for the pump rod, and the end wall 13 is provided with an annular opening 22 of such size that the replaceable cylinder or liner may pass therethrough. Projecting from the outer face 23 of the wall 13, studs 24 are shown by which a head or end plate, not illustrated, is bolted over the opening 22.

In the form of our cylinder-piston mechanism adapted to be employed with old pumps, the head customarily held in place by the studs 24 is removed and replaced by a ring or flange 25 which supports a tubular cylinder chamber extension wall 26. The wall 26 is shown threaded into the ring 25 at 27. The outer end of the wall 26 is threaded at 28 to receive a closure cap or head 30 provided with a hub 31 having a smc-oth concentric bore 32 at the inner end thereof and a threaded bore 33 extending outwardly from the smooth bore 32. From the opening 21 in the end wall 12 the customary packing member is removed and is replaced by a closure in the form of a fitting 34 having a bore 35 and a counterbore 36 adapted to receive packing which is compressed by a gland 37. The inner end of the fitting 34 has a counterbore 38, and an outwardly fiared wall 40 is formed at the inner end of the bore 35. The tting 34 is also provided with a radially and downwardly projecting boss 41 having a threaded opening 42 from which a passage 43 extends to the ared wall 40. A check valve member 44 is connected to the threaded opening 42 by means of a tting 45 having an externally threaded projection 46 and a valve seat 49. The check valve member 44 comprises a tubular wall 47 having internal threads 48 at both ends thereof and a. diametrally constricted, centrally disposed wall portion 50 with conical valve seats 51 and 52 formed at the ends of the constricted portion 50. A valve ball 53 is placed above the wall 50 so as to engage the seat 51. In the lower end of the tubular member 47 a plug 54 is screwed, this plug having a valve seat 55 in its upper end for receiving a valve ball 56. When the seat 51 becomes worn, the member 44 may be inverted so that the valve ball 53 will rest against the seat 55, and the valve bali 56 will rest against the seat 52. The plug 54 has a central passage 57 with a threaded counterbore 58 at its lower end to which fluid supply piping 60 is secured in the manner shown.

In the threaded bore 33 of the head 30 a clamping fitting 61 is screwed, this clamping fitting consisting of a cylindrical bar 62 having a reduced projection 63 which ends in a flange 64, there being an axial opening 65 extending through the bar 62 and said projection 63. A cap 66 fits over the projection 63 and is held in place by a screw 67 which is threaded into the outer end of the opening 65. A cylindrical space 68 which exists between the outer wall of the projection 63 and the cylindrical wall of the cap 66 communicates with the opening 65 through radial openings 70. An externally threaded projection 71 extends downwardly from the cap 66 and is adapted to receive a check valve member 44 which connects to the fiuid supply piping 60 through a branch pipe 73.

In the cylinder chamber 14 or" the pump 10 and the cylinder chamber extension wall 26, our improved cylinder-piston mechanism 74 is secured, this cylinder-piston mechanism consisting of a cylinder member 75 and a piston member 76. The cylinder member 75 includes an outer cylinder wall 77, the ends of which are engaged by spiders 78 and 80. From the peripheral walls 81 of the spiders 78 and 80, which peripheral walls are provided with cylindrical flanges or walls 82, inner tubular walls 83 and 84 project inwardly into the ends of the outer cylinder wall 77. The inner tubular members 83 and 84 are sufficiently smaller than the outer tubular wall 77 to form cylindrical auxiliary spaces 85 and 86. The piston member 76 includes a body 87 having piston rings 88 mounted therein and being shouldered at its ends, as indicated at 90, to support tubular walls 91 and 92 which respectively project into the cylindrical spaces 85 and 86. The spider 78 is of convex conical conguration and includes diagonal spokes 93 extending between the peripheral wall 81 thereof and a concentric hub 94. The outer end 95 of the hub 94 is of such size that it will t the counterbore 38 in the fitting 34 and has a bore 96 extending inwardly from a aring wall 97. At the inner end of the hub 94 is a counterbore 98 which receives and supports a tube extending from the annular chamber 101. Formed between the faces 40 and 97 are passages 102 which extend through the spokes 93 and connect with the leftward end of the space 85. A piston rod 103 extends leftwardly from the piston 76 through the tubular member 100, the bore 96, the chamber 101, the bore 35, and the packing means to a reciprocating means which is not shown. The piston rod 103 comprises an inner portion 105 of large diameter and an outer portion 106 of smaller diameter. The large portion 105 of the piston 103 and the tubular member 100 are so proportioned that a thin annular space 107 exists therebetween, such space 107 communicating with an auxiliary space 108 of variable volume and the pumping space 110 within the cylinder member 75 adjacent the leftward face of the piston body 87.

The spider 80 includes radially extending spokes the space 86. The cylinder-piston mechanism is centralized in the piston chamber by engagement of the hubs of the spiders 78 and 80 respectively with the counterbore 38 and the bore 32. To hold the projection 95 on the hub 94 tightly against a gasket placed in the bottom of the counterbore 38,

the clamping fitting 61 is adapted to be screwed tightly against a gasket 120 which is placed between the rightward end of the hub 113 and the leftward end of the member 61. To prevent leakage through the threads of the threaded bore 33, we provide a ring nut 121 adapted to compress packing 122 against the outer end of the hub 31 within which the threaded bore 33 extends.

The cooperating walls 83 and 91 and the cooperating walls 84 and 92 overlap, as indicated, so that therebetween annular passages 125 and 126 are formed communicating respectively between the auxiliary space 85 and the pumping space 127 lying to the right of the piston body 87, the spaces 85, 86, 110, and 127 each forming a chamber of variable volume, the volumes thereof varying in accordance with the movement of the piston member 76.

To prevent leakage of uid through the annular space 130 around the cylinder 77, we place packing 131 against the rightward shoulder 132 of the inwardly projecting annular wall 20 and compress this packing by means of a gland ring 133 which is forced leftwardly by means of three screws 134 which have threads 135 adapted to engage threaded lugs 136 which project radially inwardly from the inner end of the wall 26. The outer ends 137 of the screws 134 project through packing means, such as shown at 138, in the head 30.

For lubricating the slidably engaging faces of the cylinder-piston mechanism, we provide a grease tube 140 which has a grease inlet fitting 141 at its outer end and projects inwardly through packing means 142 in the head 30 and passes through the annular space 143 between the wall 26 and the wall 77 to an elbow tting 144 which threads into an opening 145 in the central portion of the wall 77. The auxiliary spaces 85, 86, and 108 are provided for the purpose of maintaining bodies of protective fluid in such position that these bodies of fluid will prevent the uid or material pumped from engaging the frictionally engaging surfaces of the cylinder member 75 and the piston member 76, and also for producing a fluid motion which will move away from the frictionally engaging surfaces! materials being pumped. The fiuid is supplied through the piping 60 at a pressure which may be just suiiicient to overcome the frictional head of the passages through which the iiuid must pass from the piping 60 to the auxiliary spaces 85, 86, and 108, but must at all times be greater than the pressure of fluid entering the pump 10 through the inlet valves thereof. The check valve means shown in Fig. 1 prevent an outward flow of uid and thereby insure that there will at all times be a positive or forward movement of the fluid to the spaces 85, 86, and 108; therefore, as the piston member 76 moves rightwardly, the protective fluid, such as clear water, will now into the spaces 85 and 108 through the passages 102 and 96 due to the enlargement of these spaces 85 and 108. During this time the space 86 will decrease in volume, and the protective fluid contained therein will be forced at relatively high velocity through the annular passage 126, thereby washing the inner face of the tubular member 92. At the end of the rightward stroke of the piston member 76, the infiow of protective uid into the spaces 85 and 108 and the flow of uid to be pumped into the pumping space 110 will cease, and upon leftward movement of the piston member 76 and the contents of the spaces 85, 108, and 110 will be forced therefrom, the contents of the spaces 85 and 108 passing respectively through the annular passages 125 and 107 into the pumping space 110, and the contents 0I' the pumping space 110 being forced through the openings between the spokes 93 of the spider 78 and through the fluid passage 17 of the pump. The fluid discharged from the rightward pumping space 127, when the piston member 76 moves rightwardly, passes through the spider and then through the annular space or passage 143 between the walls 26 and 77 to the fluid passage 18 of the pump.

It will be perceived by the construction shown that bodies of protective fluid are maintained at all times during the operation of the pump in the auxiliary chambers and 86 existing between the engagement areas of the piston and cylinder and the pumping spaces 110 and 127. By engagement areas of the piston and cylinder we mean the surfaces of the piston and cylinder which are in actual frictional engagement. In the form of the invention shown the circumferential face of the entire piston structure constitutes the engagement surface thereof, but the engagement surface of the cylinder wall 77 is only that portion thereof which is engaged by the piston 87.

In Fig. 6 of the drawings we have shown an alternative cylinder-piston construction embodying the principles of our invention relative to providing an auxiliary chamber or space between the sealing faces of the piston and cylinder and the pumping space within the cylinder. In Fig. 6 we show cooperating cylindei` members 150 and 151 which join together at the joint 152, there being counterbores 153 in the inner ends of said cooperating cylinder members 150 and 151 which form an annular space 154 when the cylinder members 150 and 151 are joined together, as shown. Slidable in the annular space 154 is a piston 155 having a central wall 156 equipped with sealing rings, such as rings 157, and extending outwardly frcm the ends of the central wall 156 are cylindrical walls 158 which are of such length that they overlap the faces 160 of the cylinder members 150 and 151 lying adjacent the annular space 154. Between the outer walls of the cylindrical walls 158 and the surfaces 160, annular spaces 161 are provided for communication of the auxiliary spaces 162 and 163 lying between the sealing face 164 of the piston 155 and the pumping lspaces 165 and 166 within the cylinder members 150 and 151 adjacent the ends of the piston 155. For delivery of a protective fluid to the spaces 162 and 163, we employ passages 168 which are preferably provided with means for positively feeding fluid into the spaces 162 and 163, such as check valves as shown in Fig. 1. When the piston 155 is reciprocated by a means such as a piston rod 170, the auxiliary spaces 162 and 163 expand and contract, and in so doing receive fluid through the passages 168 and eject this fluid through the annular spaces 161 into the pumping spaces 165 and v166 of the cylinder-piston mechanism, protecting the sealing face 164 and the face 171 of the annular space 154 from wear due to abrasive or other foreign materials.

Although we have herein shown and described our invention in simple and practical form, it is recognized that certain parts or elements thereof are representative of other parts, elements, or mechanisms which may be used in substantially the same manner to accomplish substantially the same results; therefore, it is to be understood that the invention is not to be limited to the details disclosed herein but is to be accorded the full scope of the following claims.

We claim as our invention:

1. In equipment of the character described, the combination of a cylinder-piston mechanism including a cylinder and a piston forming a pumping space of variable Volume, said cylinder and said piston having walls adapted for telescopic engagement in an engagement area, and said cylinder and said piston walls forming an auxiliary space of variable volume between said engagement area and said pumping space decreasing in volume as said pumping space decreases in volume; and means for feeding a fluid to said auxiliary space.

2. In equipment of the character described, the combination of: a cylinder-piston mechanism including a cylinder and a piston forming a pumping space of variable volume, said cylinder and said piston having walls adapted for telescopic engagement in an engagement area, and said cylinder and said piston walls forming an auxiliary space between said engagement area and said pumping space decreasing in Volume as said pumping space decreases in volume, said auxiliary space being in communication with said pumping space so as to permit passage of uid from said auxiliary space to said pumping space as said piston is moved in a direction to decrease the volume of said auxiliary space; and means for feeding a protective fluid to said auxiliary space.

3. In equipment of the character described, the combination of: a cylinder-piston mechanism including a cylinder and a piston forming a pumping space of variable volume, said cylinder and said piston having co-engaging walls in an engagement area, and said cylinder and said piston walls defining a collapsible auxiliary space of variable dimension between said engagement area and said pumping space decreasing in volume as said pumping space decreases in volume to force fluid from said auxiliary space into said pumping space during the forward movement of the piston; and means for feeding a protective fluid to said auxiliary space, said means comprising walls forming a fluid passage and means for preventing an outward liow of uid through said passage.

4. In equipment of the character described, the combination of: a cylinder-piston mechanism including a cylinder and a piston forming a pumping space of variable volume; walls on said cylinder and said piston having co-engagement in an engagement area, said cylinder and said piston walls dening a collapsible auxiliary space between said engagement area and said pumping space decreasing in volume as said pumping space decreases in volume, said auxiliary space being in communication with said pumping space so as to permit passage of fluid from said auxiliary space to said pumping space as said piston is moved in a direction to decrease the volume of said auxiliary space; and means for feeding a protective fluid to said auxiliary space, said means comprising walls forming a fluid passage and a check valve for preventing an outward flow of fluid through said passage.

5. A cylinder-piston mechanism for pumps of the character described, including: a cylinder member having an outer Wall and an inner wall projecting inwardly from the end of said outer wall, there being a space between said inner and outer walls; a piston slidable in said cylinder member, said piston having a tubular wall projecting into said space; a piston rod projecting from said piston and through the end of said cylinder member; a packing member in the end of said cylinder member for preventing leakage around said rod; means forming a chamber of variable volume around said rod adjacent said packing member; and walls forming a separate uid passage connecting a source of fiuid to said space and said chamber of variable volume.

6. A cylinder-piston mechanism for pumps of the character described, including: a cylinder member having an outer wall and an inner wall projecting inwardly from the end of said outer wall, there being a space between said inner and outer walls; a piston slidable in said cylinder member, said piston having a tubular wall projecting into said space; a piston rod projecting from said piston and through the end of said cylinder member, there being a rod port in the end of said cylinder member through which said piston rod extends, said cylinder member and said rod having overlapping walls forming a chamber of variable volume adjacent the inner end of said rod port; and walls forming a separate fluid passage connecting a source of fluid to said space and said chamber of variable volume.

7. A cylinder-piston mechanism for pumps of the character described, including: a cylinder member having an outer wall and a pair of inner walls projecting inwardly from the ends of said outer wall, there being a space between each of said inner walls and said Outer wall; a piston slidable in said cylinder member', having tubular walls projecting into said spaces; a piston rod projecting from said piston and through one end of said cylinder member, there being a rod port in the end of said cylinder member through which said piston rod extends, said cylinder member and said rod having overlapping walls forming a chamber of variable volume adjacent the inner end of said rod port; and walls forming a separate fluid passage connecting a source of fluid to said spaces and said chamber of variable volume.

8. A cylinder-piston mechanism for pumps of the character described, including: a cylinder member; walls on said cylinder providing a space therebetween; a piston slidable in said cylinder member, said piston having a tubular wall projecting into said space; a piston rod projecting from said piston and through the end of said cylinder member, said cylinder member and said rod having overlapping walls forming a chamber of variable volume adjacent said end of said cylinder member; and walls forming a separate uid passage connecting a source or" fluid to said space and said chamber of variable volume.

LUD'WIG STOESLING. 

